/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/


#include "itkFastMarchingImageFilterBase.h"
#include "itkFastMarchingThresholdStoppingCriterion.h"
#include "itkTextOutput.h"
#include "itkTestingMacros.h"
#include "itkCommand.h"


namespace
{
// The following class is used to support callbacks
// on the filter in the pipeline that follows later
class ShowProgressObject
{
public:
  ShowProgressObject(itk::ProcessObject * o) { m_Process = o; }
  void
  ShowProgress()
  {
    std::cout << "Progress " << m_Process->GetProgress() << std::endl;
  }
  itk::ProcessObject::Pointer m_Process;
};
} // namespace

int
itkFastMarchingImageFilterRealTest1(int itkNotUsed(argc), char * itkNotUsed(argv)[])
{

  itk::OutputWindow::SetInstance(itk::TextOutput::New().GetPointer());

  // Create a Fast Marching image filter object
  using PixelType = float;
  constexpr unsigned Dimension = 2;

  using FloatImageType = itk::Image<PixelType, Dimension>;

  using CriterionType = itk::FastMarchingThresholdStoppingCriterion<FloatImageType, FloatImageType>;

  using FastMarchingType = itk::FastMarchingImageFilterBase<FloatImageType, FloatImageType>;

  CriterionType::Pointer criterion = CriterionType::New();
  criterion->SetThreshold(100.);

  FastMarchingType::Pointer marcher = FastMarchingType::New();

  ITK_EXERCISE_BASIC_OBJECT_METHODS(marcher, FastMarchingImageFilterBase, FastMarchingBase);


  marcher->SetStoppingCriterion(criterion);

  ShowProgressObject                                    progressWatch(marcher);
  itk::SimpleMemberCommand<ShowProgressObject>::Pointer command = itk::SimpleMemberCommand<ShowProgressObject>::New();
  command->SetCallbackFunction(&progressWatch, &ShowProgressObject::ShowProgress);
  marcher->AddObserver(itk::ProgressEvent(), command);

  using NodePairType = FastMarchingType::NodePairType;
  using NodePairContainerType = FastMarchingType::NodePairContainerType;

  // Set up alive points
  NodePairContainerType::Pointer alive = NodePairContainerType::New();

  NodePairType node_pair;

  FloatImageType::OffsetType offset0 = { { 28, 35 } };

  itk::Index<Dimension> index;
  index.Fill(0);

  node_pair.SetValue(0.0);
  node_pair.SetNode(index + offset0);
  alive->push_back(node_pair);

  node_pair.SetValue(42.0);
  index.Fill(200);
  node_pair.SetNode(index); // this node is out of range

  alive->push_back(node_pair);

  marcher->SetAlivePoints(alive);

  // Set up trial points
  NodePairContainerType::Pointer trial = NodePairContainerType::New();
  node_pair.SetValue(1.0);

  index.Fill(0);
  index += offset0;

  index[0] += 1;
  node_pair.SetNode(index);
  trial->push_back(node_pair);

  index[0] -= 1;
  index[1] += 1;
  node_pair.SetNode(index);
  trial->push_back(node_pair);

  index[0] -= 1;
  index[1] -= 1;
  node_pair.SetNode(index);
  trial->push_back(node_pair);

  index[0] += 1;
  index[1] -= 1;
  node_pair.SetNode(index);
  trial->push_back(node_pair);

  node_pair.SetValue(42.0);
  index.Fill(300); // this node is out of range
  node_pair.SetNode(index);
  trial->push_back(node_pair);

  marcher->SetTrialPoints(trial);

  // Specify the size of the output image
  FloatImageType::SizeType size = { { 64, 64 } };
  marcher->SetOutputSize(size);

  // Set up a speed image of ones
  FloatImageType::Pointer    speedImage = FloatImageType::New();
  FloatImageType::RegionType region;
  region.SetSize(size);
  speedImage->SetLargestPossibleRegion(region);
  speedImage->SetBufferedRegion(region);
  speedImage->Allocate();

  itk::ImageRegionIterator<FloatImageType> speedIter(speedImage, speedImage->GetBufferedRegion());
  while (!speedIter.IsAtEnd())
  {
    speedIter.Set(1.0);
    ++speedIter;
  }

  marcher->SetInput(speedImage);

  // Turn on debugging
  marcher->DebugOn();

  // Update the Fast Marching filter
  ITK_TRY_EXPECT_NO_EXCEPTION(marcher->Update());


  // Check the results
  FloatImageType::Pointer output = marcher->GetOutput();

  itk::ImageRegionIterator<FloatImageType> iterator(output, output->GetBufferedRegion());

  bool passed = true;

  double threshold = 1.42;
  while (!iterator.IsAtEnd())
  {
    FloatImageType::IndexType tempIndex = iterator.GetIndex();
    tempIndex -= offset0;

    double distance = 0.0;
    for (unsigned int j = 0; j < Dimension; j++)
    {
      distance += tempIndex[j] * tempIndex[j];
    }
    distance = std::sqrt(distance);

    auto outputValue = static_cast<double>(iterator.Get());

    if (distance > itk::NumericTraits<double>::epsilon())
    {
      if (itk::Math::abs(outputValue) / distance > threshold)
      {
        std::cout << "Error at index [" << iterator.GetIndex() << "]" << std::endl;
        std::cout << "Expected scaled output value be less than: " << threshold
                  << ", but got: " << itk::Math::abs(outputValue) / distance
                  << ", where output: " << itk::Math::abs(outputValue) << "; scale factor: " << distance << std::endl;
        passed = false;
      }
    }
    ++iterator;
  }


  if (passed)
  {
    std::cout << "Test passed!" << std::endl;
    return EXIT_SUCCESS;
  }
  else
  {
    std::cout << "Test failed!" << std::endl;
    return EXIT_FAILURE;
  }
}
